Surfacing apparatus



June 7, 1932. H. R. sTRATFoRD 1,852,103A

SURFACING APPARATUS I Filed Jan. 9. 1929 1 u ornegs" and related ends, said invention,

Pafnted June 7,l 1932 UNITED STATESLVPATENT ,ori-ICE HERBERT R. STRATFOBD, F CLEVELAND, OHIO, ASSIGNR T0 '.'IIEl STRATMORE COM- rm, or CLEVELAND, omo, A conronArIoN or omo snnrncmo Arrann'rus l Application led January 9, 1929. Serial No. 331,355.

The present invention,relating, as indicated, to surfacing apparatus, is more partlcularly directed to a new and improved semipermanent element for use in surfacing or abrading such surfaces as wood and metal panels andpanels coated with various materials. The principal object of the present invention is the provision of a composite unitary supporting pad and abrasive element for use in portable surfacing machines characterized by the application of the abrasive di- Y lrectly to the su porting pad and the ability to re-apply the a rasive as it may be worn or reiioved from the'operating portion of the a v p To the accomplishment of the foregoing then, consists of the means hereinafter fully described and particularly pointed out in the claims; g the annexed drawing and the following description setting forth in detail'certain structureembodying the invention, such disclosed means constituting, however, but one ofvarious mechanical forms in which 'the principle of the invention may be used.

In said annexed drawing Fig. 1 is a partial central vertical section through my improved composite abrasive element and suppgrting ad; Fig. 2 is a plan view of the lower sur ace of the element of Fig. 1; Fig. 3 is a similar view showing amodification ofthe same; and Fig.l 4 is apartial central sectionv showing another modification of the element of Fig. 1.

The object of the present invention'is the provision of a combined supporting pad and abrasive element to be used therewith in which abrasive may be recoated on the pad at those portions from which the abrasive is worn during use so that a single supporting structure may beemployed indefinitely with repeated recoatings. l l

Referring now to Fig. 1, I have shown a supporting-pad lintended to be secured to the extending shaft (not shown) of a-portable surfacing machine.

be formed of rubber, felt, reinforced rubber Yor similar material, must have some sli ht amount of exibility 5o and is ordinarily supported by one or more of felt or rubber,

inexpensive and satisfactory This pad 1, which mayv and/or compressibihty lmolded su reinforcing plates 2 and 3. The amount of compressibility and flexibility o f thissupporting pad depends in each case upon the particular work for which it is intended and may bev readily varied by the reinforcing means employed with the pad proper, aswell as by the nature and thickness of the material forming the pad. In the pad shown the pad are a series of spaced concentric grooves 5, 6 and 7. These encircling grooves serve the double purpose ofjproviding a clearing space for the abrasive which is worn from the surface of the pad and 'the materiaLwhich is worn from the surface of the article 'being operated uponand for providing increased flexibility in the pad. -Wherethe pad is formed for example, these grooves may be incorporated in the pad during its manufacture, and during the application' of the layer or coating of adhesive and abrasive ilabrasive grains is then applied to thef'adhef,4 sive to produce an abrasive coating over the As the *pad 'is ao' operating portion of the pad. ordinarily employed against the work only the radially outer portion is engaged and theabrasive is removed from this ortion first. After the removal of substantia ly all of the abrasive -this portion of the pad may be recoated with adhesive and abrasive and may be used over and over, providing a relatively composite supporting -pad and abrasive element. A

In Fig. 3 .I have shown radial grooves 10 as well as a circumferential groove 11, and various other arrangements o f employed in thesurface of duce greater or less-flexibility and more or less clearance space for the removed material and abrasive. l f v In Fig. 4 `I have shown a modicationof grooves may be` the pad to pro`` `proper 1 may be formed of rubber in which a mask may be applied to the lowersurface 4 thepad just described, which consistsof al ppo'rting pad 15 formed of rubberor simar material and'providedwith a series'of recesses 16 having undercut portions 17. A composition consisting of adhesive and abrasive is filled into these openings and allowed to harden, thus providing a multiplicity of relatively solid abrasive plugs set into the compressible and/0r flexible support 15. In this form of composite article the material which forms the support, namely the rubber or similar material, must be of a na- Eture permitting it to wear oif as the abrasive wears o and this may be accomplished by the introduction into the material of a cern tain amount of abrasive material. l The pad of Fig. 4 may, after a time, lose its plugs of combined abrasive and adhesive, and in this case these may be renewed 0f course by refilling the recesses with adhesive and abrasiye and allowing the latter to set.

Other modes of applying the principle of my invention may be employed insteadof the one explained, change being made as regards the structure herein disclosed, provided the means stated by any of the following claims or the equivalent of such stated means be employed.

I therefore particularlypoint out and distinctly claim as my invention 1. A composite abrasive element consisting of a thin flexible backing dise, a com-f pressible supporting pad mounted on said disc and provided on its exposed surface with a series of recesses and raised lands between said recesses, said pad having abrasive properties"` for an appreciable depth.

2. A composite abrasiveelement consisting of a compressible supporting pad provided with a narrow annular weakened area concentric with the axis of the element` and spaced from the periphery of the element to increase the flexibilityl of the element along the line of the weakened area, said pad haviing labrasive properties for' an appreciable ept 3. A composite abrasive element consistin of a compressible supporting pad provide with'a recess imparting weakness thereto along an approximately annular line concentric with the axis' of the element to increase the flexibility of the element along such line, said pad having abrasive properties for an appreciable depth. 'lqQSigned by me, this 2nd day of January,

HERBERT R. STRATFORD. 

